DEFECTS OF GRAPHENE
The scientists are trying to solve, in various ways, one of the defects of graphene, that has raised some doubts about the use of this material. The defect is linked to the good conductivity of the material and consists of the considerable difficulty that occurs when a graphene transistor must be " turned off ". In practice, in the Digital Electronics Field, while a silicon transistor can be “switched on and off ”, taking respectively the values "0" and "1", a graphene transistor can go, at best, from "very turned on", to "little turned on”. Therefore, it is necessary to limit the electrons flow.
The advantages of graphene are well known and they have been measured in different laboratories of research, all over the world. However, the properties of graphene have been observed on nanoscale, at the level of a single graphene sheet, that often is free of defects or contaminants of any kind. These properties degrade rapidly, when we move from a single sheet to macroscopic materials, based on graphene. In particular, the electrons flow is disturbed due to the defects that are in the interface between adjacent sheets.
Professors Ting Zhu, associate at the Georgia Institute of Technology and Jun Lou, associate at the Rice University, USA, in order to understand better the limits of graphene practical use, have done some studies on an extended surface of grafene. Their studies have focused on the useful resistance of the material, limited by its fracture resistance. During the tests, the graphene has been broken up, in order to estimate the strength of the force required in the action; the results of the tests have been published in the “Nature Communications“ journal.
The challenge of all researchers is to exploit, in a useful and reliable way, the properties of graphene, in order to develop more and more the new technology based on this nano-material.